G503 Military Vehicle Message Forums

Carburetor experts in DMV area

Carburetor experts in DMV area

Posted: Mon Jun 15, 2015 12:07 pm

by Ardbeg10

Hello,
My GPW's carb (539s) has been running rich since I got it. I've gone through two sets of spark plugs (Autolite 295) in the last two months. The plugs end up with heavy carbon deposit, no oil or anything else just carbon. I tried adjusting the mixture screw on the carb all the way in (from 1.5 turn) but that doesnt seem to help, in fact when the mixture screw is turned all the way in it doesnt even stall the engine which according to G503 forums should happen in a properly functioning carb. I have a feeling that the metering rod is set incorrectly and is constantly feeding excess amount of gasoline.

So the question I have, is there an easy way to adjust a carb which is running rich and/or adjust the metering rod setting? I'm trying not to open up the carb and rebuild it but will explore that option is need be.

P.S. Currently with carb running rich, I have no problem with idling, the engine runs smooth with a an occasional puttiing sound and I can easily do 50mph as long as the spark plugs are good.